For less than 100 calories, one hard-boiled egg delivers at least 10 percent of your recommended daily intake of quality protein and vitamins A and B-12. Part of the vitamin A comes in the form of lutein and zeaxanthin, which are antioxidants that keep your eyes healthy. Hard-boiled eggs are low in total fat, but high in cholesterol, so limit your consumption if you have high cholesterol or heart disease.
One of the benefits of eating a hard-boiled egg is that it's low in calories and doesn't gain any extra calories from frying or added ingredients such as cheese. One large hard-boiled egg contains 78 calories. If you're strictly watching caloric intake, go with a small egg. As a general guideline, you will gain about 10 additional calories every time the size of the egg increases from small to medium, large, extra large and jumbo. A small egg has 54 calories and the jumbo-sized egg jumps to 90 calories.
Calories From Fat
Even though eggs are high in cholesterol, they are not high in total or saturated fats. You'll get 5 grams of total fat and 2 grams of saturated fat from one large hard-boiled egg. Since 1 gram of fat contains 9 calories, that means 45 calories in a large, hard-boiled egg come from fat. Twenty-five to 35 percent of your total daily calories should come from fat, according to the American Heart Association. Saturated fats should account for less than 7 percent of your total calories. Based on a 2,000 calorie-a-day diet, one hard-boiled egg only supplies 2 percent of your total fat and 1 percent of your saturated fat.
You'll get 186 milligrams of cholesterol from one large hard-boiled egg. If you're healthy, you should keep cholesterol under 300 milligrams daily, so just one large egg provides 62 percent of an entire day's cholesterol. If you already have high cholesterol or heart disease, limit cholesterol to fewer than 200 milligrams daily. The Harvard School of Public Health recommends limiting egg consumption to no more than three yolks a week if you have diabetes or heart disease. The cholesterol you eat actually has a small impact on levels of cholesterol in your blood. For this reason, many healthy people can tolerate one egg daily as long as they don't eat other high-cholesterol foods.
All of the fat is in the egg yolk, so you can eliminate cholesterol concerns and about 76 percent of the total calories if you eat only egg whites. Egg white still retains about half of a hard-boiled egg's 6 grams of total protein. However, eliminating the yolk also means you'll lose a significant amount of the egg's vitamins. Most of the egg's folate and vitamin's B-6 and B-12 -- as well as all of its vitamin A -- are in the yolk.
Once eggs are hard cooked, they spoil more quickly than fresh eggs, according to the United States Department of Agriculture. For this reason, refrigerate them within two hours of cooking the eggs and use them within one week. It's best to refrigerate raw eggs in the carton as soon as you get home from the store. Check the egg for cracks at the store because bacteria can get into the egg through the crack. If the eggs crack on the trip home, you don't have to discard them. Instead, crack them into a clean container as soon as you get home. Keep the container covered and use the eggs within two days.